The invention relates generally to a switch and in particular, to a micro-electromechanical system switch.
The use of micro-electromechanical system (MEMS) switches has been found to be advantageous over traditional solid-state switches. For example, MEMS switches have been found to have superior power efficiency, low insertion loss, and excellent electrical isolation.
MEMS switches are devices that use mechanical movement to achieve a short circuit (make) or an open circuit (break) in a circuit. The force required for the mechanical movement can be obtained using various types of actuation mechanisms such as electrostatic, magnetic, piezoelectric, or thermal actuation. Electrostatically actuated switches have been demonstrated to have high reliability and wafer scale manufacturing techniques. Construction and design of such MEMS switches have been constantly improving.
Switch characteristics such as standoff voltage (between the contacts of the switch) and pull-in voltage (between the actuator and the contact) are considered for design of MEMS switches. Typically, while trying to achieve higher stand-off voltage presents a contradicting characteristic of a decreased pull-in voltage. Traditionally, increasing beam thickness and gap size increases stand-off voltage. However, this increases the pull-in voltage as well and that is not desirable.
There exists a need for an improved MEMS switch that exhibits substantially high standoff voltage and at the same time substantially lower pull-in voltage without additional complexity in the switch design.